Abstract:
Based on the measured acceleration response under Typhoon Kompasu, the modal parameters of the 356 m Shenzhen Meteorological Gradient Tower (SMGT) are identified. The Non-dominated Sorting Genetic Algorithm Ⅱ(NSGA-Ⅱ), which is a fast and elitist genetic algorithm, is applied to update the finite element (FE) model of SMGT. The results show that the vibra? tion modes of SMGT are very dense, and the involvement of cable vibration modes is obvious. The fundamental frequencies of SMGT in X and Y directions are 0.614 Hz and 0.603 Hz, respectively, and the damping ratio of the first 3 order bending modes are about 1%~2%. The tower density and cable elastic modulus have a significant effect on the modal frequency and mode shape of SMGT, the lineic mass of high-rise cable and tower elastic modulus also have a certain influence, while the cable tension has a relatively low influence on the modes of SMGT. The wind-induced response of the updating FE model is higher than that of initial model, and closer to the actual measurement, which verifies the accuracy of the updating FE model.